The present invention relates to a clamping device comprising a collar, suitable for being disposed around objects to be clamped, and having at least one pair of projecting lugs, the device further comprising tightening means suitable for co-operating with lugs of said pair to move them relative to each other in a manner such as to clause the diameter of the collar to decrease.
In particular, the tightening means are of the nut and bolt type. Collars of this type, e.g. for clamping together two smooth tubes disposed end-to-end, are known from Patent Application EP 1 181 477. Conventionally, the collar includes a belt portion relative to which the two lugs serving for tightening are upstanding. The belt portion is disposed around the object(s) to be clamped, and the lugs, which for raised lips, are disposed facing each other to define a slot between them of width that is decreased during tightening.
In the collar described in the above-mentioned patent, the lugs formed by said lips are situated in the immediate vicinity of the edges of the above-mentioned slot. Even though such collars are generally satisfactory, it has been observed that, for certain demanding applications, the tightening might lose some of its effectiveness because, firstly, the co-operation between the tightening means, in particular means having bolts, might not take place in the desired manner, in particular due to the bolts not being guided properly, and, secondly, the lugs might bend under the effect of the tightening forces.